The Vector Core's primary function wili be to supply the recombinant AAV (rAAV)virus stocks and subclone new plasmids that are used in this Program. The Vector Core will use validated quality control assays to insure the purity and specific activity of the rAAV preparations used in the Program. In addition, the Core will implement improved methods for purifying rAAV vector stocks and generating higher yields of recombinant AAV virus at they become available. The Vector Core Laboratory will make high titer concentrated rAAV serotype 2, 5, or hybrid 5/2 vector stocks as described by the Projects by Meyer and King of this proposal. Vectors will be made by the helper free, plasmid transfection method developed at UF in part by the Core PI. rAAV vectors will be purified and then titered for infectious virus by the infectious center assay and for particles by slot blot hybridization. To determine the purity of the rAAV vector stocks, the Core will subject all stocks to silver stain gel analysis. The extent of replication competent AAV (rcAAV) contamination, if any, will be assayed by infectious center assay.